config/configure: ignore utimensat on GNU/kFreeBSD.

Even though we'll find it, it won't work.

See also:

  http://bugs.debian.org/651104
  http://lists.debian.org/debian-bsd/2011/03/msg00063.html

Signed-off-by: Gonéri Le Bouder <goneri@rulezlan.org>
[rlb@defaultvalue.org: adjust indentation, comments, and message.]
Signed-off-by: Rob Browning <rlb@defaultvalue.org>
t/compare-trees: check rsync capability support correctly.

Handle older versions of rsync (where nothing was printed), and for
newer versions, check for "no FOO" rather than "FOO", since FOO will
always be listed one way or the other.

Handle ACL and xattr support independently.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>
Tested-by: Zoran Zaric <zz@zoranzaric.de>
Reviewed-by: Zoran Zaric <zz@zoranzaric.de>